The Events Service manages the creation and maintenance of Event subscriptions. More...

#include <events.h>

Inheritance diagram for JAUS::Events:

Classes
class	Callback
	Method to put hooks into Event Service to be notified when a new event has been received. More...
class	Child
	Defines the interface for Services that inherit from the Events Service. More...
class	Subscription
	Describes information about an Event that is being produced or subscribed to by the Component. More...
Public Types
enum	Type { Periodic = 0, EveryChange }
Public Member Functions
	Events ()
	Constructor.
	~Events ()
	Destructor.
virtual void	Shutdown ()
	Shutsdown the Service.
bool	RequestEveryChangeEvent (const Address &provider, const Message *query, const unsigned int waitTimeMs=Service::DefaultWaitMs)
	Requests an Every Change event subscription from the component specified.
bool	RequestPeriodicEvent (const Address &provider, const Message *query, const double desiredPeriodicRate=1.0, const double minimumPeriodicRate=0.9, const unsigned int waitTimeMs=DefaultWaitMs)
	Requests an Periodic event subscription from the component specified.
void	SignalEvent (const UShort reportMessageCode, const bool changeOnly=true)
	Signals to the Event Service that the type of data has changed and any EveryChange type events should be generated.
void	SignalEvent (const Subscription &info, const bool changeOnly=true)
	Signals to the Event Service that the type of data has changed and any EveryChange type events should be generated.
bool	CancelSubscription (const Address &id, const UShort reportMessageCode, const unsigned int waitTimeMs=Service::DefaultWaitMs)
	Method used to cancel any existing subscriptions from a component.
bool	CancelSubscription (const Address &id, const UShort reportMessageCode, Byte eventID, const unsigned int waitTimeMs)
	Method used to cancel any existing subscriptions from a component.
bool	HaveSubscription (const UShort reportMessageCode, const Address &id, const bool verifyWithQuery=false, const unsigned int waitTimeMs=Service::DefaultWaitMs) const
	Method used to confirm, or check to see if an event subscription exists.
bool	HaveSubscribers (const UShort reportMessageCode) const
	Method used to check if there are subscribers for a type of event.
virtual bool	IsDiscoverable () const
virtual void	Receive (const Message *message)
	Processes message received by the Service. If not supported, then message is passed to inheriting services.
virtual Message *	CreateMessage (const UShort messageCode) const
	Attempts to create the message desired. Only message supported by this Service can be created by this Service.
virtual void	CheckServiceStatus (const unsigned int timeSinceLastCheckMs)
	Method called periodically by external classes and is used to verify subscriptions are still valid.
void	SetEventSubscriptionCheckThreshold (const Time::Stamp timeMs=5000)
Subscription::List	GetSubscriptions (const Address &source=Address(), const UShort reportType=0) const
	Gets a list of event subscriptions.
Subscription::List	GetSubscriptions (const UShort reportType) const
	Gets a list of event subscriptions.
Subscription::List	GetProducedEvents (const UShort reportType) const
	Gets a list of event subscriptions being produced by this service.
void	RegisterCallback (Events::Callback *callback)
	Method to register a callback for an event.
virtual void	PrintStatus () const
	Prints status info about the Service to the console.
Static Public Attributes
static const std::string	Name = "urn:jaus:jss:core:Events"
	String name of the Service.

Detailed Description

The Events Service manages the creation and maintenance of Event subscriptions.

This service allows clients to subscribe to changes in the information provided by report messages supported by services that derive from this service. When a client succesfully creates an event, an "Internal Event" occurs when the event creation critera are met, and as a result the matching Event is sent to the subscribing client.

Definition at line 63 of file events.h.

Member Enumeration Documentation

enum JAUS::Events::Type

Enumerator:

Periodic
EveryChange

Definition at line 68 of file events.h.

Constructor & Destructor Documentation

Events::Events ( )

Constructor.

Definition at line 269 of file events.cpp.

Events::~Events ( )

Destructor.

Definition at line 283 of file events.cpp.

Member Function Documentation

bool Events::CancelSubscription	(	const Address &	id,
		const UShort	reportMessageCode,
		const unsigned int	waitTimeMs = `Service::DefaultWaitMs`
	)

Method used to cancel any existing subscriptions from a component.

If the reportMessageCode is set to 0, then all subscriptions from the specified component are canceled.

Parameters:

[in]	reportMessageCode	The type of data for the event.
[in]	id	The ID of the component generating the event that needs to be canceled.
[in]	waitTimeMs	How long to wait for a confirm or reject response to be received.

Returns:: True on success, false on failure.

Definition at line 709 of file events.cpp.

bool Events::CancelSubscription	(	const Address &	id,
		const UShort	reportMessageCode,
		Byte	eventID,
		const unsigned int	waitTimeMs
	)

Method used to cancel any existing subscriptions from a component.

If the reportMessageCode is set to 0, then all subscriptions from the specified component are canceled.

Parameters:

[in]	reportMessageCode	The type of data for the event.
[in]	id	The ID of the component generating the event that needs to be canceled.
[in]	eventID	Specific event ID.
[in]	waitTimeMs	How long to wait for a confirm or reject response to be received.

Returns:: True on success, false on failure.

Definition at line 788 of file events.cpp.

void Events::CheckServiceStatus ( const unsigned int timeSinceLastCheckMs ) [virtual]

Method called periodically by external classes and is used to verify subscriptions are still valid.

Parameters:

[in] timeSinceLastCheckMs Number of milliseconds since the last time this method was called.

Reimplemented from JAUS::Service.

Definition at line 1445 of file events.cpp.

Message * Events::CreateMessage ( const UShort messageCode ) const [virtual]

Attempts to create the message desired. Only message supported by this Service can be created by this Service.

Parameters:

[in] messageCode Message to create.

Returns:: Pointer to newly allocated Message data, NULL if message is not supported by the Service.

Implements JAUS::Service.

Definition at line 1397 of file events.cpp.

Events::Subscription::List Events::GetProducedEvents ( const UShort reportType ) const

Gets a list of event subscriptions being produced by this service.

It's possible to filter by source and by message report type. If source is a 0 ID (invalid), then all event producers are considered, otherwise event producers with matching ID as source.

To filter by type, set reportType to a non 0 value, and only events of the type will be returned.

Parameters:

[in] reportType The type of event messages to get info on. set to 0 for any events.

Returns:: List of subscriptions the service has.

Definition at line 1574 of file events.cpp.

Events::Subscription::List Events::GetSubscriptions ( const UShort reportType ) const

Gets a list of event subscriptions.

It's possible to filter by source and by message report type. If source is a 0 ID (invalid), then all event producers are considered, otherwise event producers with matching ID as source.

To filter by type, set reportType to a non 0 value, and only events of the type will be returned.

Parameters:

[in] reportType The type of event messages to get info on. set to 0 for any events.

Returns:: List of subscriptions the service has.

Definition at line 1537 of file events.cpp.

Events::Subscription::List Events::GetSubscriptions	(	const Address &	source = `Address()`,
		const UShort	reportType = `0`
	)		const

Gets a list of event subscriptions.

It's possible to filter by source and by message report type. If source is a 0 ID (invalid), then all event producers are considered, otherwise event producers with matching ID as source.

To filter by type, set reportType to a non 0 value, and only events of the type will be returned.

Parameters:

[in]	source	ID of the source of the event to get subscriptions from. Set to 0.0.0 for any source.
[in]	reportType	The type of event messages to get info on. set to 0 for any events.

Returns:: List of subscriptions the service has.

Definition at line 1496 of file events.cpp.

bool Events::HaveSubscribers ( const UShort reportMessageCode ) const

Method used to check if there are subscribers for a type of event.

Parameters:

[in] reportMessageCode The type of data for the event.

Returns:: True if the subscription exists, false otherwise.

Definition at line 921 of file events.cpp.

bool Events::HaveSubscription	(	const UShort	reportMessageCode,
		const Address &	id,
		const bool	verifyWithQuery = `false`,
		const unsigned int	waitTimeMs = `Service::DefaultWaitMs`
	)		const

Method used to confirm, or check to see if an event subscription exists.

Parameters:

[in]	reportMessageCode	The type of data for the event.
[in]	id	The ID of the component providing the event. If set to 0.0.0.0 then any component with the type of event is checked.
[in]	verifyWithQuery	If true, a Query Events message is sent to the component to verify that the event actually exists.
[in]	waitTimeMs	How long to wait in ms for a response to be recevied when verifyWithQuery is true.

Returns:: True if the subscription exists, false otherwise.

Definition at line 869 of file events.cpp.

virtual bool JAUS::Events::IsDiscoverable ( ) const [inline, virtual]

Implements JAUS::Service.

Definition at line 201 of file events.h.

void Events::PrintStatus ( ) const [virtual]

Prints status info about the Service to the console.

Reimplemented from JAUS::Service.

Definition at line 681 of file events.cpp.

void Events::Receive ( const Message * message ) [virtual]

Processes message received by the Service. If not supported, then message is passed to inheriting services.

This Service supports the following message: Cancel Event, Confirm Event Request, Create Event, Event, Query Events, Reject Event Request, Report Events, UpdateEvent.

Parameters:

[in] message Message data to process.

Reimplemented from JAUS::Service.

Definition at line 954 of file events.cpp.

void Events::RegisterCallback ( Events::Callback * callback )

Method to register a callback for an event.

Parameters:

[in] callback Pointer to callback instance (is not deleted by service).

Definition at line 1599 of file events.cpp.

bool Events::RequestEveryChangeEvent	(	const Address &	provider,
		const Message *	query,
		const unsigned int	waitTimeMs = `Service::DefaultWaitMs`
	)

Requests an Every Change event subscription from the component specified.

Parameters:

[in]	provider	The component that will provide the event.
[in]	query	The type of data to query (used to determine type of report information desired).
[in]	waitTimeMs	How long to wait for a response from the component sending confirmation/rejection.

Returns:: True if subscription created, false otherwise.

Definition at line 361 of file events.cpp.

bool Events::RequestPeriodicEvent	(	const Address &	provider,
		const Message *	query,
		const double	desiredPeriodicRate = `1.0`,
		const double	minimumPeriodicRate = `0.9`,
		const unsigned int	waitTimeMs = `DefaultWaitMs`
	)

Requests an Periodic event subscription from the component specified.

Parameters:

[in]	provider	The component that will provide the event.
[in]	query	The type of data to query (used to determine type of report information desired).
[in]	desiredPeriodicRate	The desired periodic update rate for the event.
[in]	minimumPeriodicRate	The minimum periodic rate that you will accept, anything less than this number and the event will be canceled.
[in]	waitTimeMs	How long to wait for a response from the component sending confirmation/rejection.

Returns:: True if subscription created, false otherwise.

Definition at line 473 of file events.cpp.

void JAUS::Events::SetEventSubscriptionCheckThreshold ( const Time::Stamp timeMs = 5000 ) [inline]

Definition at line 209 of file events.h.

void Events::Shutdown ( ) [virtual]

Shutsdown the Service.

Reimplemented from JAUS::Service.

Definition at line 293 of file events.cpp.

void Events::SignalEvent	(	const UShort	reportMessageCode,
		const bool	changeOnly = `true`
	)

Signals to the Event Service that the type of data has changed and any EveryChange type events should be generated.

Any time your report data changes, and your Service is a child of the Event Service, you should signal the change in the data using this method.

Parameters:

[in]	reportMessageCode	The type of data that has changed.
[in]	changeOnly	If true, only Every Change events are signaled. This is the default behavior.

Definition at line 596 of file events.cpp.

void Events::SignalEvent	(	const Subscription &	info,
		const bool	changeOnly = `true`
	)

Signals to the Event Service that the type of data has changed and any EveryChange type events should be generated.

Any time your report data changes, and your Service is a child of the Event Service, you can signal the change in the data using this method.

Parameters:

[in]	info	The specific event to trigger.
[in]	changeOnly	If true, only Every Change events are signaled. This is the default behavior.

Definition at line 641 of file events.cpp.

Member Data Documentation

const std::string Events::Name = "urn:jaus:jss:core:Events" [static]

String name of the Service.

Definition at line 66 of file events.h.

The documentation for this class was generated from the following files:

jaus++/2.0/include/jaus/core/events/events.h
jaus++/2.0/src/jaus/core/events/events.cpp

JAUS::Events Class Reference

Classes

Public Types

Public Member Functions

Static Public Attributes

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation